What are active and inactive volcanoes?

A:

Quick Answer

Active volcanoes are those that have erupted recently or regularly erupt, and inactive volcanoes are those that have not erupted for a long time. The exact time distinction between active and inactive volcanoes differs between experts.

Keep Learning

Currently active volcanoes are volcanoes that are erupting presently, and there are almost always some erupting throughout the world. Active volcanoes are expected to erupt in the near future on a relatively regular schedule. Some people consider volcanoes active if they have erupted in the past 100 years, but others do not classify a volcano as inactive or dormant until hundreds or thousands of years have passed.

Dormant and inactive are often used interchangeably, but they have subtle differences. Dormant volcanoes are expected, and have the ability, to erupt in the future. They may have a long cycle between eruptions during which they are dormant. Inactive volcanoes are usually not expected to erupt in the future and have not erupted in recent history.

Dormant and inactive volcanoes can become extinct after many years. This happens when a volcano moves away from its magma source or its source becomes empty. The shifting of tectonic plates can move volcanoes away from the source, which results in extinct volcanoes that have no chance of erupting.

Related Questions

Hot melted rocks collect under the Earth's surface and when the pressure becomes too hard, the Earth's skin breaks, and a volcano erupts. The melted rock inside the Earth is called magma, but when it comes out in an eruption, it is called lava.

Volcanologists wear heavy boots, long-sleeved shirts and heavy work gloves in order to protect their bodies from lava near a volcano. According to Oregon State University, volcanologists might also wear jeans, a rock-climbing helmet for protection and a gas mask.

The inside of a volcano has one or more vents through which gas and lava flow during eruptions. Below the vent is the magma, which is the molten rock that flows upward due to the divergence or convergence of tectonic plates in the Earth's crust. The number of vents and shape of the buildup of magma inside the magma chamber depends upon the type of volcano.

Oshima as an island stratovolcano with a large caldera on its summit. Stratovolcanoes are conical volcanoes built up by many layers of hardened lava and volcanic ash, with steep profiles and periodic eruptions.